JPH05230525A - Fused salt chamber integrated with sludge remover - Google Patents

Abstract

PURPOSE:To decrease the settlement of the high-melting temp. components into a piping and to remove sludge with high efficiency by providing a sludge removing space integral with a fused salt bath in the upper part of a fused salt bath chamber body and attachably and detachably disposing a sludge removing element therein. CONSTITUTION:The fused salt contg. the sludge in the fused salt chamber 1 is supplied from a supply pipe 6 to a resting cylinder 11 of the sludge removing element 5. The sludge components settle in the resting cylinder 11 and are sent to the sludge removing space between inside and outside cylinders 15 and 10. The sludge components settle on a sludge receiving tray 16 and further, the sludge components nearly completely settle on the receiving tray 16 while the sludge components are transferred upward between inclined plates 14. The fused salt from which the sludge is removed bleeds out of small holes 20 in the upper part of the outside cylinder 10 and returns to the fused salt bath chamber 1. The inside cylinder 15, the inclined plates 14 and the outside cylinder 10 are pulled upward when the sludge accumulates on the receiving tray 16. The fused salt returns from small holes 21 provided in the receiving tray 16 to the fused salt bath chamber 1. The sludge remaining in the receiving tray 16 is removed from a sludge plug 12 on the bottom.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molten salt tank in which a molten salt tank and a sludge removing device are integrated and which is capable of continuously and efficiently removing sludge generated in a salt bath during metal heat treatment.

[0002]

2. Description of the Related Art When a metal is heat-treated with a molten salt, sludge is generated in the molten salt over time, which adversely affects the quality of treated parts. Therefore, it is necessary to remove the sludge. Conventionally, in general, operation is stopped, sedimentation at the bottom of the molten salt tank, sludge floating in the bath is collected and removed with a metal wire mesh, and a dish-shaped container is sunk at the bottom of the tank. (Sludge pan) to collect or settle, gently lift this dish and remove it, or continuously pump it up from the molten salt tank without stopping the operation, in a separately prepared sludge removal device Is used to remove sludge, and the molten salt after sludge removal is returned to the tank.

Regarding a continuous sludge removing method, a sludge removing device using a sludge removing device provided separately from the molten salt tank is described in Japanese Patent Application No. 55-29134. However, in the invention described in this publication, the piping of the salt bath and the sludge removal tank for circulation has a high melting temperature contained in the molten salt bath, for example, sodium carbonate or the like gradually deposits on the piping and blocks the piping. In some cases, molten salt may overflow from the removing device, which is dangerous.
Such a phenomenon is caused by a high melting temperature component that is solidified and separated on the outer periphery of the pipe due to the equipment being stopped on the weekend, or when the treated parts are put into the molten salt tank, the molten salt temperature in the tank decreases and The melting temperature component precipitates and deposits on the pipe, so that it gradually occurs during operation. However, such an environment is unavoidable in actual operation, and as a measure to prevent the deposition of this high melting temperature component, it is necessary to operate while monitoring the blockage of the pipe even if the pipe is kept warm and the heater is heated. Very inefficient in terms of facility management. In addition, deposits on the pipe must be cleaned by heating or removing the pipe and cleaning with steam, which requires a long time for maintenance.

It is an object of the present invention to provide a molten salt tank which can reduce the deposition of high melting temperature components on piping as much as possible, and can remove sludge with high efficiency.

[0005]

DISCLOSURE OF THE INVENTION The present invention is directed to a slag space portion which is part of the upper portion of the molten salt bath main body and is integrated with the molten salt bath, and a removable slag element disposed therein. The above-mentioned problems are solved by a molten salt tank in which a sludge removing device consisting of is integrated. In the present invention,
The sludge removing device may include a heating means and a temperature control device which are independent of the molten salt tank. Also,
The sludge removing device is a stationary tube arranged in the center for calming the molten salt pumped from the molten salt tank and supplied from a swingable supply pipe, and is fixed to the bottom of the stationary tube. Sludge pan, an inner cylinder fitted to the outer circumference of the stationary cylinder, an outer cylinder with its lower end fitted to the sludge pan, and a small hole in the upper outer circumference where molten salt circulates, and between these inner cylinder and outer cylinder And an inclined plate that is inclined from below the small hole portion of the outer cylinder toward the upper portion of the inner cylinder. In these molten salt tanks, the sludge removing device and the molten salt bath shall be manufactured by processing a thick plate made of pure titanium or nickel alloy, and the slag element shall be made of pure titanium or nickel alloy. May be

[0006]

Since the sludge removing device is integrated in the molten salt tank of the present invention, a supply pipe for supplying the molten salt pumped up from the molten salt tank to the sludge removing device is provided with a conventional sludge removing device. It can be shortened compared to the case where a tank is installed separately, and because it is heated by heat transfer and radiant heat from the furnace body and the sludge removal device integrated with the furnace body,
The high melting temperature component is not deposited in the supply pipe without taking any special measures. Further, since the molten salt after sludge removal is directly returned to the molten salt tank through the small holes of the slag element, a molten salt return pipe is unnecessary. Further, if the sludge removing device and the molten salt bath are manufactured by processing a thick plate made of pure titanium or nickel alloy, electric heat from the heating source to the molten salt is higher than that of the conventional lining structure. The effect is significantly improved. Further, if the slag element is made of pure titanium or nickel alloy,
Molten salt adherence to the slag element is reduced and clogging of small holes is prevented.

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an example of a molten salt tank according to the present invention. In FIG. 1, 1 is a molten salt tank, 2 is a heater for a sludge removing device, 3 is heating control means for a sludge removing device, 4 Is a sludge removing apparatus main body, 5 is a slag element, 6 is a molten salt supply pipe which can be swung, connected to a pump, 7 is a molten salt heating source, 8 is a molten salt furnace shell, and 9 is a thermocouple. As described above, the molten salt tank of the present invention forms a part of the so-called molten salt tank main body, and comprises a slag space portion integrated with the molten salt bath and a removable slag element disposed therein. The sludge removing device is integrated.

FIG. 2 shows an example of a removable slag element disposed in the slag space part with a part cut away, and FIG. 3 is a perspective perspective view thereof. These Figure 2
In FIG. 3, a stationary tube 11 is arranged in the center of the slag element 5, an opening 13 is provided in the lower part of the stationary tube 11, and a small hole 21 is formed in the outer periphery of the bottom thereof. The opened sludge tray 16 is fixed. An inner cylinder 15 is fitted on the outer circumference of the stationary cylinder 11, and an outer cylinder 10 having a small hole 20 is fitted on the outer circumference of the upper part of the sludge receiving tray 16. The inner cylinder 15 and the outer cylinder 10 are An inclined plate 14 is provided between the small holes 20 of the outer cylinder 10 and the upper part of the inner cylinder 15 so as to be inclined. As a result, the slag element 5 itself can be detached from the slag space and the slag element 5 can be removed.
The inner cylinder 15, the outer cylinder 10 and the inclined plate 14 can be integrally separated from the stationary cylinder 11.

Considering the life of the element, easiness of handling, and effect, the slag element 5 has sufficient heat resistance and corrosion resistance, is lightweight and has a long molten salt flow path in a small space, and has a good sludge separation effect. Desired. Therefore, it is preferable that these properties can be sufficiently exhibited in a thin plate and that the metal is easily available. Specifically, pure titanium,
Nickel alloy is good. Further, by using a thick plate instead of using the molten salt tank as a lining, there is an advantage that the electric heating effect from the heating source to the molten salt is significantly improved.
Since the slag element 5 is constantly in contact with the molten salt, if the element itself is affected by oxidation, nitriding, carburizing, etc. as a result of being subjected to chemical reaction and erosion, the scale on which the surface of the outer cylinder 10 is peeled off or the element surface Sludge in the molten salt is likely to adhere due to rough skin, so that the small holes 20 formed in the outer cylinder 10 may be clogged. For this reason, the element is preferably made of a chemically extremely stable metal such as pure titanium or nickel alloy.

In the present invention, the inclined plate 14 is provided to lengthen the molten salt flow passage in the element and to facilitate sludge separation in this passage. In the present invention, in order to further enhance the sludge separation effect, for example, as disclosed in Japanese Patent Application No. 55-29134,
The sludge in the molten salt may be separated by circulating the molten salt in the molten salt bath through the slag element containing the sludge collecting member formed by rolling the fibrous thin wire into a lump.
Further, a collecting member may be set above and below the inclined plate 14 according to the property of sludge.

In this way, the stationary cylinder 1 of the slag element 5 is
Molten salt containing sludge in the molten salt tank is pumped into the inside of 1 by a pump and supplied from a supply pipe 6. The sludge component of the molten salt settles in the stationary cylinder 11 and is sent from the opening 13 to the slag space between the inner and outer cylinders. The sludge component settles in the sludge pan 16 and the sludge component is almost completely settled in the sludge pan 14 while being transferred between the inclined plates 14 and the molten salt from which the sludge has been removed is in the upper part of the outer cylinder 10. It exudes from the small holes 20 and is directly returned to the molten salt bath.
Thus, after repeating such an operation, when sludge is accumulated in the sludge receiving tray 16, the tip of the supply pipe 6 is rotated to leave the stationary tube 11 and the sludge receiving tray 16, and the inner tube 15, the inclined plate 14 and the outer tube. Pull the tube 10 upward. At this time, the molten salt is discharged into the small holes 21 provided in the sludge tray 16.
Then, the sludge returns to the molten salt bath, and the sludge remains in the sludge tray 16 as it is, and the sludge is removed from the sludge plug 12 provided at the bottom of the sludge tray 16. After that, the inner cylinder 15, the outer cylinder 10, the inclined plate 14, the stationary cylinder 11, the sludge plug, etc. are washed with water and dried, and in some cases, a collecting member is set and repeatedly used.

During these operations, the slag element integrated with the molten salt tank may be provided with a heating means and a temperature control means independent of the molten salt tank, and independent heat management may be performed by these.

Next, the effect was tested using a salt bath carbonitriding tank for iron-based parts having the illustrated construction. Diameter 1000m
In a molten salt bath equipped with a sludge removing device having a depth of 1500 mm and a sludge removing device, a molten salt containing a mixture of alkali cyanic acid and an alkali carbonate was dissolved and kept at 580 ° C. to operate the slag element. A carbon steel shaft having a gross weight of about 350 kg was put therein, and holding for 90 minutes was set as one step, and three steps were repeated for 7 hours. When the molten salt was supplied to the slag element at a flow rate of 800 L / H, the treatment quality after the three steps was as good as the nitriding layer 15 to 20μ and the porous layer 1/3, and the water insoluble content was about
It was possible to collect 1000 g of sludge. Also, 2 mm
Compared to the case where the titanium material of 12 mm is lined in a 12 mm stainless steel molten salt outer tank, in the case of 12 mm nickel-based alloy,
It took 15 minutes to raise the temperature to 580 ° C after the parts were put in.

[0014]

As described above, according to the present invention, the length of the molten salt supply pipe is short, clogging of the supply pipe is reduced, and the molten salt return pipe is omitted. There is no need to consider clogging of the
This has the effect that maintenance management is greatly simplified and sludge removal of molten salt that can maintain the heat treatment quality of metal at high quality can be performed continuously and easily.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a molten salt tank according to the present invention.

FIG. 2 is an explanatory view showing an example of a slag element according to the present invention with a part cut away.

3 is a perspective perspective view of an example of the slag element shown in FIG. 2. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molten salt tank 2 Heating heater 3 Heating control means 4 Sludge removing device main body 5 Slag element 6 Supply pipe 7 Molten salt heating source 8 Molten salt furnace shell 9 Thermocouple 10 Outer cylinder 11 Stationary cylinder 12 Sludge plug 13 Opening 14 Inclined plate 15 Inner cylinder 16 Sludge tray 20 Small hole 21 Small hole

Claims (5)

[Claims] 1. A sludge removing device, which forms a part of the upper portion of the molten salt bath main body and is integrated with a molten salt bath, and a sludge removing device including a removable sludge element disposed therein. Molten salt tank. 2. The molten salt tank according to claim 1, wherein the sludge removing device includes a heating means and a temperature control device which are independent of the molten salt tank. 3. A stationary cylinder, wherein the sludge removing device is arranged in the center for calming the molten salt pumped from a molten salt tank and supplied from a swingable supply pipe, and its stationary state. A sludge tray fixed to the bottom of the tube, an inner tube fitted to the outer circumference of the stationary tube and an outer tube having a lower end fitted to the sludge tray and a small hole through which molten salt circulates on the outer circumference of the inner tube. The molten salt tank according to claim 1 or 2, further comprising: an inclined plate provided between the cylinder and the outer cylinder so as to incline from a lower portion of the outer cylinder toward an upper portion of the inner cylinder. 4. The molten salt tank according to claim 1, wherein the sludge removing device and the molten salt bath are manufactured by processing a thick plate made of pure titanium or nickel alloy. 5. The molten salt tank according to claim 3, wherein the slag element is made of pure titanium or nickel alloy.